<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <title>Document</title>
        <style>
            * {
                margin: 0;
                padding: 0;
                list-style: none;
                border: none;
                background-color: transparent;
            }
            button {
                padding: 6px 30px;
                margin: 10px;
                border: 1px solid #000;
            }
            :root {
                --primary-color: skyblue;
                --danger-color: red;
            }
            .primary {
                background-color: var(--primary-color);
            }
            .danger {
                --danger-color: yellow;
                background-color: var(--danger-color);
            }
        </style>
    </head>
    <body>
        <button class="primary">按钮一</button>
        <button class="danger">按钮二</button>
    </body>
</html>
